The present disclosure relates generally to image-guided tissue sampling and, more particularly, to a system and method for Computed Tomography (CT)-guided needle biopsy for sampling lung nodules with respiratory motion.
Lung cancer is the most common cause of cancer-related death in men world-wide and the second most common cause of cancer-related death in women, resulting in 1.3 million deaths per year. Early diagnosis and detection is critical to reduce morbidity and mortality rates in high-risk individuals who are screened for lung cancer. Lung nodules, the precursor to lung cancer, are often detected by imaging examinations, such as X-ray and CT. However, it is not always possible to tell from these imaging studies whether a lesion is benign or cancerous. To confirm the diagnosis, a needle biopsy is often performed to obtain tissue samples from the suspicious area for microscopic examinations.
CT-guided needle biopsy has become a dominant method of obtaining tissue samples from lung nodules for lung cancer diagnosis and is performed by a specially trained interventional radiologist. The patient will lie on a CT table, and receives a local anesthesia injection to numb the needle path. The suspicious nodule is located through a pre-operative CT scan, and the safest needle path will be planned based on the scan. The patient will be required to stay still and hold his/her breath during the procedure. Using intra-operative CT scans to confirm the positions of the nodule and needle, the clinician inserts the needle through the skin, advance it to the target nodule, and removes tissue samples. CT-guided needle biopsy is minimally invasive, eliminating the added morbidity of open surgery and requiring no general anesthesia. The procedure is generally not painful. The patient quickly recovers able to return home and resumes their usual activities the same day.
Tissue sampling accuracy and patient safety are critical in the CT-guided needle biopsy of lung nodules, and impose serious challenges. Accurate needle placement depends on the clinician's skill and consistency and the patient's compliance. The nodule size and location contribute to the difficulty in needle placement. Although ideally located nodules as small as 4 mm have been successfully biopsied in case reports, as a general rule, lesions ≤8 mm are very difficult to approach and successfully biopsy. The diagnostic accuracy generally decreases with smaller lesions and longer needle paths. Moreover, to implement a rapid, safe and accurate biopsy, it is necessary for the patient to remain still and repeatedly hold his/her breath during needle manipulations. Breath holding can be a significant problem when a lesion is close to the diaphragm because the lung nodule can be displaced up to 20 mm or even higher during a respiratory cycle. Thus, it is highly challenging to perform biopsies in patients who have difficulties in holding their breath, which accounts for about 10%-15% of the entire patient pool. In addition, the procedure duration ranges from 15 minutes to over an hour, depending on CT, cytology availability, nodule accessibility and patient compliance. Inaccurate needle positioning and insufficient patient compliance necessarily increase the number of needle passes and occurrence of complications such as pneumothorax and bleeding. These issues can be overcome by extremely experienced physicians. However, the widespread availability of these physicians is limited.
Image-guided robots have been growing as an important technological advance to assist image-guided percutaneous procedures. Various robotic percutaneous systems have been developed or researched, from general-purpose percutaneous systems to those specialized for neurosurgery, prostate interventions, breast biopsy and therapy, renal access and other similar procedures, under the guidance of different imaging modalities such as CT/fluoroscopy, ultrasound and MR. Generally, the needle path is determined by the clinician based on initial imaging, usually by choosing the target and skin-entry points; the robot moves the needle to a starting position and aligns it to the pre-planned needle path; and the needle is inserted to the desired depth manually or robotically. Automatic feedback control of needle movement has also been proposed, such as the needle movement adjustment based on CT and MR image processing and the more real-time needle trajectory control based on ultrasound image processing, single-plane CT image processing and tracking sensor feedback. Moreover, there is a category of robotic percutaneous systems, which combine the manual adjustment and robotic needle alignment/driving and can be controlled by the clinician using a joystick using real-time image display.
However, the above systems focus on handling generally static organs and lack integrated control schemes for needle placement on moving targets, such as lung nodules with respiratory motion. Thus, known systems cannot obtain high targeting accuracy and short procedure duration with respect to moving targets. Particularly, in the scenario of CT-guided needle biopsy of moving lung nodules, it may result in an increase in the number of needle passes, occurrence of complications and radiation exposure on the patient.
Therefore, there is a need to implement a CT-guided robotic needle biopsy on moving targets, such as lung nodules with respiratory motion, with improved biopsy accuracy and reduced biopsy duration, which does not require arduous patient compliance during the interventional procedure, such as breath holding. Accordingly, in accordance with the present disclosure, the incidence of complications can be reduced, patient safety can be improved, and human intervention can be minimized.